WASHINGTON (AP) — Chuck Hagel — Republican, twice-wounded Vietnam combat veteran and former Nebraska senator — faces his first major hurdle in his bid to become the nation's defense secretary as a bitterly divided Senate Armed Services Committee pushes toward a vote on his nomination.

The panel is scheduled to meet Tuesday afternoon to discuss and vote on President Barack Obama's choice to succeed Defense Secretary Leon Panetta, who is stepping down after four years as CIA director and Pentagon chief. Senate Majority Leader Harry Reid, D-Nev., is pressing for a full Senate vote on either Wednesday or Thursday.

Hagel faces fierce opposition from Republicans who have challenged his past statements and votes on Israel, Iran, Iraq and nuclear weapons. Committee Republicans forced a delay in the expected committee vote last week when they pressed Hagel for more information about his personal finances.

The panel's chairman, Sen. Carl Levin, D-Mich., said the GOP demands were beyond the scope of those traditionally asked of previous nominees, Republican and Democrat — a point echoed by his Republican colleague, Sen. John McCain of Arizona. Levin set a committee vote that will probably break along party lines — 14 Democrats for Hagel, 12 Republicans against their former colleague — just hours before Obama's State of the Union address to Congress.

More critical to whether Republicans drag out the nomination is the closed-door, weekly Republican luncheon Tuesday where Senate Minority Leader Mitch McConnell, R-Ky., will determine whether GOP lawmakers have the inclination and votes to filibuster a president's Cabinet choice. Such a move would be unprecedented in the Senate, where Republicans and Democrats have argued that a president's nominee should get an up or down vote.

Late Monday, McCain met privately with several committee Republicans and urged them not to filibuster the Hagel nomination, arguing that it would set a bad precedent and pointing out that the roles could be reversed someday with a Republican president and GOP-controlled Senate.

"I'm encouraging my colleagues if they want to vote against Sen. Hagel that's one thing and that's a principled stand," McCain told a group of reporters. "We do not want to filibuster. We have not filibustered a Cabinet appointee in the past and I believe that we should move forward with his nomination, bring it to the floor and vote up or down."

McCain has not said how he would vote on the nomination, but has indicated he was learning against confirmation.

Sen. Jim Inhofe of Oklahoma, the top Republican on the Armed Services Committee, said he is determined to do everything in his power to scuttle the nomination, though he told reporters he does not want to string out the process. Sen. Lindsey Graham, R-S.C., has signaled that he would block the nominations of Hagel and CIA Director-designate John Brennan if he doesn't get more answers about the deadly raid on the U.S. diplomatic mission in Benghazi, Libya, last September.

"I'm insisting that the president answer ... what he did that night. That's all. It would take five minutes to answer my question," Graham told reporters. "It's the only leverage I have."

The White House pushed back Monday, with spokesman Jay Carney insisting the administration had answered lingering questions about Libya and the president's actions on that fateful day.

"What is unfortunate here is the continuing attempt to politicize an issue, in this case through nominees that themselves had nothing to do with Benghazi, and to do so in a way that only does harm to our national security interests," Carney said. "Sen. Hagel, Mr. Brennan, they need to be confirmed."

All 55 Democrats are expected to back Hagel, and two Republicans — Sens. Thad Cochran of Mississippi and Mike Johanns of Nebraska — have said they will vote for the nominee. At least five Republicans, including McCain, have said they oppose a filibuster despite their reservations or opposition toward the nominee.

Sen. Orrin Hatch, R-Utah, said he would not support a filibuster.

"Chuck and I have been friends. I have to say I was disappointed in his performance" at his confirmation hearing, Hatch said.

Hagel seemed ill-prepared under withering cross-examination from committee Republicans in nearly eight hours of testimony on Jan. 31. He was repeatedly pressed about past statements and votes on Israel, Iran and nuclear weapons, with GOP lawmakers suggesting he wasn't sufficiently supportive of Israel or anti-Iran.

About a dozen Republicans have said they will oppose their former colleague, and several others have indicated they are likely to vote no.

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